A fingerprint identification module, a manufacturing method and driving method thereof, and a display device. The fingerprint identification module includes: a driving backplate, including a substrate, identification circuits on the substrate, the identification circuits having a first electrode pad, a second electrode pad; acoustic units including: a first electrode; a piezoelectric film layer positioned on the side, close to the driving backplate, of the first electrode; a second electrode positioned on the side, close to the driving backplate, of the piezoelectric film layer; a first lead-out terminal electrically connected with the first electrode; a second lead-out terminal electrically connected with the second electrode; cavities being in one-to-one correspondence to the acoustic units, the cavities positioned between the second electrodes and the substrate, and one side face, away from the substrate, of cavity being defined by at least one side face, close to the substrate, of the second electrode.
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1. A fingerprint identification module, comprising: a driving backplate, comprising a substrate and a plurality of identification circuits positioned on the substrate, the identification circuits having a first electrode pad and a second electrode pad; a plurality of acoustic units, the acoustic units being in one-to-one correspondence to the identification circuits, and the acoustic units comprising: a first electrode; a piezoelectric film layer positioned on a side, close to the driving backplate, of the first electrode; a second electrode positioned on a side, close to the driving backplate, of the piezoelectric film layer; a first lead-out terminal electrically connected with the first electrode; and a second lead-out terminal electrically connected with the second electrode; the first lead-out terminals being electrically connected with the first electrode pads, and the second lead-out terminals being electrically connected with the second electrode pads; and a plurality of cavities, the cavities being in one-to-one correspondence to the acoustic units, the cavities being positioned between the second electrodes and the substrate, and one side face, away from the substrate, of the cavities being defined by at least one side face, close to the substrate, of the second electrode.
A fingerprint identification module includes a driving backplate with a substrate and multiple identification circuits, each having a first and second electrode pad. The module also includes multiple acoustic units, each corresponding to an identification circuit. Each acoustic unit has a first electrode, a piezoelectric film layer on the side of the first electrode facing the driving backplate, and a second electrode on the side of the piezoelectric film layer facing the driving backplate. The first and second electrodes are connected to first and second lead-out terminals, respectively, which are electrically connected to the first and second electrode pads of the identification circuits. The module further includes multiple cavities, each corresponding to an acoustic unit and positioned between the second electrode and the substrate. The cavities are defined by the side face of the second electrode closest to the substrate and the side face of the cavity farthest from the substrate. This design enables precise fingerprint detection by converting mechanical pressure from a fingerprint into electrical signals via the piezoelectric film layer, with the cavities enhancing sensitivity by allowing the piezoelectric elements to deform more freely. The identification circuits process these signals to generate a fingerprint image. The module is used in biometric authentication systems, providing secure and accurate fingerprint recognition.
2. The fingerprint identification module according to claim 1 , wherein a support portion is arranged between the piezoelectric film layer and the substrate; and in a direction perpendicular to the substrate, a highest height of the cavity is equal to a sum of heights of the first electrode pad, the first lead-out terminal and the support portion.
A fingerprint identification module includes a piezoelectric film layer and a substrate, with a cavity formed between them. The piezoelectric film layer is configured to generate an electrical signal in response to a fingerprint touch, enabling fingerprint recognition. The module also includes a first electrode pad and a first lead-out terminal electrically connected to the piezoelectric film layer, facilitating signal transmission. To enhance structural stability and performance, a support portion is positioned between the piezoelectric film layer and the substrate. In the direction perpendicular to the substrate, the highest point of the cavity aligns vertically with the combined heights of the first electrode pad, the first lead-out terminal, and the support portion. This design ensures proper spacing and alignment, optimizing the module's sensitivity and reliability. The support portion helps maintain the cavity's structural integrity while allowing the piezoelectric film layer to deform in response to fingerprint pressure, ensuring accurate signal generation. The arrangement also minimizes mechanical stress on the film layer, improving durability and performance over time. This configuration is particularly useful in compact electronic devices where space efficiency and robust fingerprint recognition are critical.
3. The fingerprint identification module according to claim 2 , wherein the support portion is located between the piezoelectric film layer and a layer where the first lead-out terminal is located.
A fingerprint identification module includes a piezoelectric film layer for capturing fingerprint data and a support portion that provides structural stability. The support portion is positioned between the piezoelectric film layer and a layer containing a first lead-out terminal, which is used to transmit electrical signals from the piezoelectric film layer to external circuitry. The module may also include a second lead-out terminal for additional signal transmission. The piezoelectric film layer converts mechanical pressure from a fingerprint into electrical signals, which are then processed to generate a fingerprint image. The support portion ensures proper alignment and mechanical integrity of the piezoelectric film layer while allowing efficient signal transmission through the lead-out terminals. This design improves the reliability and accuracy of fingerprint identification by maintaining the structural stability of the piezoelectric film layer during operation. The module is particularly useful in electronic devices requiring secure biometric authentication, such as smartphones, tablets, and access control systems. The arrangement of the support portion between the piezoelectric film layer and the lead-out terminal layer optimizes signal integrity and reduces interference, enhancing overall performance.
4. The fingerprint identification module according to claim 2 , wherein the support portion is located between the substrate and a layer where the first electrode pad is located.
A fingerprint identification module includes a substrate and a support portion positioned between the substrate and a layer containing a first electrode pad. The module is designed for capturing and processing fingerprint data, addressing challenges in maintaining structural integrity and signal accuracy in compact electronic devices. The support portion provides mechanical stability to the module, preventing deformation or misalignment of the electrode pad layer during operation. This ensures consistent electrical contact and reliable fingerprint sensing performance. The module may also include additional components such as a second electrode pad, a sensing layer, and a protective layer, all integrated to enhance durability and functionality. The support portion's placement between the substrate and the electrode pad layer optimizes space efficiency while maintaining structural robustness, making the module suitable for integration into thin and lightweight devices like smartphones or wearable electronics. The design improves resistance to environmental factors like vibration or impact, ensuring long-term reliability in fingerprint recognition applications.
5. The fingerprint identification module according to claim 2 , wherein the substrate is provided with grooves, and side walls of the grooves serve as the support portions.
A fingerprint identification module is designed to enhance the accuracy and reliability of fingerprint recognition by incorporating a substrate with grooves. The substrate serves as a base for the fingerprint sensor, and the grooves are formed with side walls that act as support portions. These support portions provide structural stability to the sensor components, ensuring precise alignment and consistent performance. The grooves may be arranged in a specific pattern to optimize the distribution of support across the sensor surface, reducing mechanical stress and improving durability. This design helps maintain the integrity of the sensor's active areas, which are responsible for capturing detailed fingerprint images. By integrating the support portions directly into the substrate, the module achieves a compact and robust structure, suitable for integration into various electronic devices. The grooves can be fabricated using standard semiconductor or microfabrication techniques, ensuring compatibility with existing manufacturing processes. This approach addresses challenges related to sensor deformation, misalignment, and signal distortion, leading to more accurate and consistent fingerprint recognition. The module is particularly useful in applications requiring high-security authentication, such as smartphones, biometric access systems, and payment terminals.
6. The fingerprint identification module according to claim 1 , wherein a side face, away from the substrate, of the cavities is at least defined by a side face, close to the substrate, of the piezoelectric film layer.
Fingerprint identification modules often require precise alignment of piezoelectric film layers with underlying cavities to ensure accurate sensing of fingerprint patterns. Misalignment or improper spacing can degrade performance, leading to inaccurate readings or reduced sensitivity. This invention addresses the challenge by defining the side face of the cavities, opposite the substrate, using the side face of the piezoelectric film layer that is closest to the substrate. This ensures consistent and precise positioning of the piezoelectric film relative to the cavities, improving the module's ability to detect and convert mechanical pressure from fingerprints into electrical signals. The cavities are structured such that their side face, furthest from the substrate, is at least partially bounded by the side face of the piezoelectric film layer near the substrate. This alignment minimizes gaps or misalignments, enhancing the module's reliability and accuracy. The piezoelectric film layer converts mechanical pressure from fingerprint ridges into electrical signals, which are then processed to generate a fingerprint image. The cavities provide structural support and may also aid in isolating individual sensing elements to reduce crosstalk. By ensuring the side face of the cavities is defined by the piezoelectric film layer, the invention improves the mechanical and electrical coupling between the film and the substrate, leading to more consistent and accurate fingerprint detection.
7. The fingerprint identification module according to claim 2 , wherein the support portions are annular support portions.
Fingerprint identification systems often require precise alignment of optical components to ensure accurate imaging of fingerprints. Misalignment can lead to poor image quality, reducing identification accuracy. To address this, a fingerprint identification module includes a support structure with annular support portions that securely hold optical components in place. These annular support portions are designed to encircle and stabilize the optical components, preventing movement or misalignment during use. The support structure may also include additional features, such as alignment guides or fastening mechanisms, to further enhance stability. By using annular support portions, the module ensures consistent optical performance, improving the reliability of fingerprint recognition. This design is particularly useful in compact devices where space constraints make traditional mounting methods impractical. The annular support portions provide a balanced and uniform distribution of force, reducing stress on the optical components and extending their lifespan. Overall, the module offers a robust solution for maintaining optical alignment in fingerprint identification systems, ensuring high-quality imaging and accurate biometric authentication.
8. The fingerprint identification module according to claim 1 , wherein the cavities are filled with air or elastic filler.
Fingerprint identification systems use sensors to capture and analyze unique ridge and valley patterns on a user's finger for authentication. A key challenge in these systems is ensuring accurate and reliable fingerprint capture, especially when the sensor surface is not perfectly flat or when external factors like pressure or environmental conditions affect the fingerprint image quality. To address this, a fingerprint identification module includes a sensor surface with multiple cavities or recesses. These cavities are designed to improve the contact between the finger and the sensor, enhancing the clarity and detail of the captured fingerprint image. The cavities can be filled with air or an elastic filler material. When filled with air, the cavities allow for slight deformation of the finger's surface, improving conformal contact and reducing distortion. When filled with an elastic filler, the material provides a cushioning effect, further enhancing the fingerprint capture process by adapting to variations in finger pressure and surface irregularities. This design ensures that the fingerprint sensor can capture high-quality images even under varying conditions, improving the overall accuracy and reliability of the identification system.
9. The fingerprint identification module according to claim 2 , wherein the acoustic unit further comprise a through hole penetrating through the corresponding piezoelectric film layer, the through hole is filled with a first connecting portion, and the first lead-out terminal is electrically connected with the first electrode through the first connecting portion.
A fingerprint identification module incorporates an acoustic unit with a piezoelectric film layer for capturing fingerprint data. The acoustic unit includes a through hole that penetrates the piezoelectric film layer, allowing for electrical connectivity. This through hole is filled with a conductive first connecting portion, which electrically links a first lead-out terminal to a first electrode on the piezoelectric film layer. The piezoelectric film layer generates electrical signals in response to acoustic waves produced by fingerprint ridges and valleys, enabling high-resolution fingerprint imaging. The through hole and connecting portion ensure reliable electrical conduction while maintaining structural integrity. This design enhances signal transmission efficiency and improves the accuracy of fingerprint recognition by minimizing signal loss and interference. The module is used in biometric security systems, mobile devices, and access control applications where precise fingerprint identification is required. The through hole and connecting portion address challenges in integrating conductive pathways within thin piezoelectric layers, ensuring robust performance in compact electronic devices.
10. The fingerprint identification module according to claim 9 , wherein a part of the second electrode is reused as the second lead-out terminal; the first connecting portion, the first lead-out terminal, and the second electrode are disposed on a same layer.
A fingerprint identification module includes a sensing array with multiple sensing units, each having a first electrode and a second electrode. The first electrode is connected to a first lead-out terminal via a first connecting portion, while the second electrode is connected to a second lead-out terminal. The second electrode is partially reused as the second lead-out terminal, reducing the need for additional conductive traces. Both the first connecting portion, the first lead-out terminal, and the second electrode are fabricated on the same layer, simplifying the manufacturing process and improving structural efficiency. This design minimizes the footprint of the module while maintaining reliable electrical connections. The module is used in electronic devices to capture and process fingerprint data for authentication purposes, addressing the need for compact, high-performance biometric sensors. The reuse of the second electrode as part of the lead-out terminal and the co-planar arrangement of components enhance integration and reduce production complexity.
11. The fingerprint identification module according to claim 1 , wherein the acoustic unit further comprise an elastic layer located on a side, facing away from the piezoelectric film layer, of the first electrode.
The invention relates to an improved fingerprint identification module that enhances acoustic signal detection for fingerprint sensing. Traditional fingerprint sensors often struggle with low signal quality due to insufficient acoustic coupling between the sensor and the user's finger. This invention addresses the problem by incorporating an additional elastic layer in the acoustic unit of the fingerprint identification module. The acoustic unit includes a piezoelectric film layer and a first electrode, and the elastic layer is positioned on the side of the first electrode that faces away from the piezoelectric film layer. The elastic layer improves acoustic coupling by conforming to the surface of the user's finger, thereby increasing the sensitivity and accuracy of fingerprint detection. The piezoelectric film layer generates electrical signals in response to acoustic waves reflected from the finger's surface, while the elastic layer ensures optimal transmission of these waves. This design enhances the overall performance of the fingerprint identification module by reducing signal loss and improving the clarity of the captured fingerprint image. The invention is particularly useful in applications requiring high-precision biometric authentication, such as smartphones, security systems, and access control devices.
12. The fingerprint identification module according to claim 1 , wherein the piezoelectric film layer is an inorganic piezoelectric film layer made of aluminum nitride, zinc oxide or lead zirconate titanate.
This invention relates to a fingerprint identification module incorporating a piezoelectric film layer for enhanced biometric sensing. The module addresses challenges in conventional fingerprint recognition systems, such as limited sensitivity, durability, and environmental robustness. The piezoelectric film layer converts mechanical pressure from finger contact into electrical signals, improving detection accuracy and reliability. The piezoelectric film layer is specifically an inorganic material, such as aluminum nitride, zinc oxide, or lead zirconate titanate. These materials offer superior mechanical strength, thermal stability, and long-term performance compared to organic alternatives. The inorganic composition ensures consistent piezoelectric response, reducing signal degradation over time and under varying environmental conditions. The module integrates this piezoelectric layer with other components to capture detailed fingerprint patterns. When a finger presses against the sensor, the piezoelectric material generates electrical signals proportional to the applied pressure, which are then processed to reconstruct the fingerprint image. This approach enhances sensitivity to fine ridges and valleys, improving identification accuracy. The use of inorganic piezoelectric materials also enhances durability, making the module suitable for harsh environments, including high humidity, temperature fluctuations, and mechanical stress. This makes the technology ideal for applications in security systems, mobile devices, and industrial authentication tools. The invention provides a robust, high-performance solution for fingerprint recognition, addressing limitations of existing sensor technologies.
13. The fingerprint identification module according to claim 1 , further comprises a control IC, transmitting traces and receiving traces, the first electrode pads are receiving electrode pads, and the second electrode pads are transmitting electrode pads; and the receiving electrode pads are electrically connected with the control IC through thin film transistor switching circuits via the receiving traces, and the transmitting electrode pads are electrically connected with the control IC via the transmitting traces.
This invention relates to a fingerprint identification module with an improved electrode pad configuration and connection structure. The module addresses challenges in fingerprint sensing technology, particularly in ensuring reliable signal transmission and reception for accurate fingerprint detection. The module includes a control integrated circuit (IC) and a sensor array with transmitting and receiving electrode pads. The first set of electrode pads functions as receiving electrode pads, while the second set functions as transmitting electrode pads. The receiving electrode pads are connected to the control IC through thin film transistor (TFT) switching circuits, which are linked via receiving traces. The transmitting electrode pads are directly connected to the control IC via transmitting traces. This configuration enhances signal integrity and reduces interference, improving fingerprint recognition accuracy. The TFT switching circuits enable selective activation of receiving electrode pads, optimizing power consumption and performance. The transmitting traces provide a direct path for signal transmission, minimizing signal loss. This design is particularly useful in compact electronic devices where space constraints and signal quality are critical. The module may be integrated into smartphones, biometric security systems, or other devices requiring high-precision fingerprint identification.
14. A display device, comprising the fingerprint identification module according to claim 1 , and further comprising a display panel; and the fingerprint identification module being located on a non-display surface of the display panel.
A display device includes a fingerprint identification module integrated with a display panel. The fingerprint identification module is positioned on a non-display surface of the display panel, such as the back or side of the device, rather than on the display surface. This configuration allows for secure and convenient fingerprint authentication without obstructing the display area. The fingerprint identification module captures fingerprint data from a user's finger when placed on the designated non-display surface, enabling biometric verification for device access, payments, or other security functions. The display panel provides visual output while the fingerprint module operates independently, ensuring seamless integration of security and display functionalities. This design improves user experience by maintaining an unobstructed display while providing secure authentication in a compact form factor. The fingerprint module may include sensors and processing components to analyze fingerprint patterns and match them against stored biometric data for authentication purposes. The overall system enhances security and usability in electronic devices such as smartphones, tablets, or other display-equipped devices.
15. A manufacturing method of the fingerprint identification module according to claim 1 , wherein the manufacturing method comprises: forming a driving backplate, wherein the driving backplate comprises a substrate and a plurality of identification circuits positioned on the substrate, and the identification circuits comprise a first electrode pad and a second electrode pad; forming a plurality of acoustic units on a carrier substrate, wherein the acoustic unit comprise a first lead-out terminal and a second lead-out terminal; and transferring the acoustic units on the carrier substrate to the driving backplate, electrically connecting the first electrode pads with the first lead-out terminals, electrically connecting the second electrode pads with the second lead-out terminals, and forming cavities between second electrodes and the substrate, wherein one side face, away from the substrate, of the cavities is defined by at least one side face, close to the substrate, of the second electrode.
This technical summary describes a method for manufacturing a fingerprint identification module. The module operates in the domain of biometric sensing, specifically for capturing and processing fingerprint data. The problem addressed is the efficient and precise assembly of acoustic units with a driving backplate to form a functional fingerprint sensor. The manufacturing method involves forming a driving backplate with a substrate and multiple identification circuits. Each identification circuit includes a first and second electrode pad. Separately, a plurality of acoustic units are formed on a carrier substrate, each with a first and second lead-out terminal. The acoustic units are then transferred from the carrier substrate to the driving backplate. During this transfer, the first electrode pads are electrically connected to the first lead-out terminals, and the second electrode pads are connected to the second lead-out terminals. Cavities are formed between the second electrodes and the substrate, with one side of the cavity defined by the side face of the second electrode closest to the substrate. This configuration ensures proper acoustic coupling and electrical connectivity for accurate fingerprint detection. The method enables precise alignment and reliable electrical connections, improving the performance and manufacturability of fingerprint identification modules.
16. The manufacturing method according to claim 15 , wherein the forming the plurality of acoustic units on the carrier substrate comprises: sequentially forming a first electrode and a piezoelectric film layer on the carrier substrate, and forming a through hole in the piezoelectric film layer; and forming the second electrode and the first lead-out terminal on a side, away from the first electrode, of the piezoelectric film layer, wherein the second electrode and the first lead-out terminal do not overlap, and the first lead-out terminal is electrically connected with the first electrode through a first connecting portion filled in the through hole; wherein the second electrode, the first lead-out terminal and the first connecting portion are formed by a same patterning process.
This invention relates to a manufacturing method for acoustic devices, specifically for producing acoustic units with improved electrical connectivity and structural integrity. The method addresses challenges in fabricating piezoelectric-based acoustic devices, such as microphones or speakers, where reliable electrical connections between electrodes and lead-out terminals are critical for performance. The process involves forming a plurality of acoustic units on a carrier substrate. First, a first electrode and a piezoelectric film layer are sequentially deposited on the carrier substrate. A through hole is then created in the piezoelectric film layer. Next, a second electrode and a first lead-out terminal are formed on the opposite side of the piezoelectric film layer from the first electrode. The second electrode and the first lead-out terminal are positioned to avoid overlapping, ensuring proper electrical isolation. The first lead-out terminal is electrically connected to the first electrode via a first connecting portion that fills the through hole. The second electrode, first lead-out terminal, and first connecting portion are all formed in a single patterning process, streamlining manufacturing and reducing misalignment risks. This approach enhances manufacturing efficiency by minimizing steps and improving precision in electrical connections, which is essential for high-performance acoustic devices. The method ensures robust structural and electrical integrity while simplifying production workflows.
17. The manufacturing method according to claim 15 , wherein before the forming the second electrode and the first lead-out terminal on the side, away from the first electrode, of the piezoelectric film layer, the manufacturing method further comprises: forming a support portion on a side, away from the first electrode, of the piezoelectric film layer, so as to form the cavities between the piezoelectric film layers and the driving backplate when the acoustic unit is transferred to the driving backplate.
This invention relates to a manufacturing method for an acoustic device, specifically addressing the challenge of forming cavities between piezoelectric film layers and a driving backplate to enhance acoustic performance. The method involves creating a support portion on the side of the piezoelectric film layer opposite the first electrode before forming the second electrode and the first lead-out terminal. This support portion ensures that when the acoustic unit is transferred to the driving backplate, cavities are formed between the piezoelectric film layers and the backplate. The cavities improve acoustic properties by allowing proper vibration and sound transmission. The method ensures precise alignment and structural integrity during the manufacturing process, preventing collapse or deformation of the piezoelectric film layers. The support portion acts as a spacer, maintaining the required distance between the film layers and the backplate. This technique is particularly useful in microelectromechanical systems (MEMS) and other acoustic devices where precise cavity formation is critical for optimal performance. The invention focuses on improving the reliability and efficiency of the manufacturing process while ensuring consistent acoustic output.
18. The manufacturing method according to claim 15 , wherein the forming the driving backplate comprises: before forming the first electrode pads and the second electrode pads on the substrate, forming a plurality of support portions on the substrate, so as to form the cavities between the piezoelectric film layers and the driving backplate when the acoustic units are transferred to the driving backplate.
This invention relates to a manufacturing method for acoustic devices, specifically addressing the challenge of forming cavities between piezoelectric film layers and a driving backplate in acoustic units. The method involves creating support portions on a substrate before forming electrode pads, which ensures proper cavity formation when the acoustic units are transferred to the driving backplate. The support portions are strategically placed to maintain structural integrity while allowing the cavities to function as intended, improving device performance. The process includes depositing and patterning conductive materials to form the electrode pads, which are essential for electrical connectivity in the acoustic units. The cavities facilitate mechanical movement of the piezoelectric film layers, enhancing acoustic output. The method ensures precise alignment and spacing of components, reducing defects and improving manufacturing yield. This approach is particularly useful in microelectromechanical systems (MEMS) where precise cavity formation is critical for optimal device operation. The invention focuses on optimizing the manufacturing steps to achieve reliable and efficient acoustic devices with consistent performance.
19. The manufacturing method according to claim 15 , wherein the forming the driving backplate comprises: forming a plurality of grooves in the substrate, so as to form the cavities between the piezoelectric film layers and the driving backplate when the acoustic units are transferred to the driving backplate; and forming a plurality of identification circuits in other regions of the substrate except regions where the grooves are located.
This invention relates to a manufacturing method for acoustic devices, specifically for producing a driving backplate with integrated cavities and identification circuits. The method addresses the challenge of efficiently fabricating a backplate structure that supports piezoelectric film layers while ensuring proper acoustic performance and device identification. The process involves forming a substrate with multiple grooves, which create cavities when the piezoelectric film layers are transferred onto the driving backplate. These cavities enhance acoustic functionality by allowing movement of the piezoelectric elements. Additionally, identification circuits are formed in regions of the substrate that do not contain grooves, enabling tracking and control of individual acoustic units during and after manufacturing. The grooves and circuits are precisely patterned to ensure structural integrity and electrical connectivity. This method improves manufacturing efficiency by integrating cavity formation and circuit integration into a single substrate, reducing assembly steps and potential misalignment issues. The resulting backplate structure supports reliable acoustic operation while providing embedded identification for quality control and device management. The technique is particularly useful in applications requiring precise acoustic control, such as microelectromechanical systems (MEMS) and sensor arrays.
20. A driving method of the fingerprint identification module according to claim 1 , wherein the driving method comprises: in a transmitting stage, controlling the first electrode pads to load a first fixed potential and the second electrode pads to load varying electrical signals; and in a receiving stage, converting ultrasonic signals reflected by a finger, through the piezoelectric film layers, into identification electrical signals, controlling the second electrode pads to load a second fixed potential, and receiving, by the first electrode pads, the identification electrical signals; and the controlling the second electrode pads to load the varying electrical signals comprises: sequentially controlling the second electrode pads to load the varying electrical signals; and when a current second electrode pad loads the varying electrical signals, controlling the plurality of adjacent second electrode pads to load the electrical signals before a preset period, so that a plurality of ultrasonic signals correspondingly converted from the plurality of electrical signals are sequentially focused at different positions.
This invention relates to a driving method for a fingerprint identification module that uses ultrasonic signals for biometric sensing. The module includes a piezoelectric film layer with first and second electrode pads. The problem addressed is improving the accuracy and efficiency of ultrasonic fingerprint detection by optimizing signal transmission and reception. The driving method operates in two stages: transmitting and receiving. During transmission, the first electrode pads are held at a fixed potential while the second electrode pads are sequentially driven with varying electrical signals. Adjacent second electrode pads are activated slightly before the current pad to focus ultrasonic signals at different positions, enhancing resolution. In the receiving stage, reflected ultrasonic signals from a finger are converted into electrical signals by the piezoelectric film layers. The second electrode pads are held at a fixed potential, while the first electrode pads receive the identification signals for processing. This approach improves fingerprint imaging by dynamically controlling signal transmission to achieve precise focusing and clear signal reception, addressing challenges in ultrasonic fingerprint sensor performance. The method ensures accurate signal generation and reception, enhancing the reliability of fingerprint identification.
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September 17, 2019
March 29, 2022
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